1. Field of the Invention
The present invention is directed generally to systems for and methods of forming walls or other structures from materials, such as cement, that are poured into molds or forms in a liquid state and subsequently harden to a solid state therein, and more particularly to methods and systems for forming insulated and/or reinforced concrete walls.
2. Description of the Related Art
Many buildings have walls including a wall material, such as cement, that transitions from a liquid state to a solid state by drying, curing, and/or cooling. The wall may be constructed by pouring the wall material into a wall forming structure or system where the wall material solidifies to form a solid wall. To add strength to these walls, solid reinforcement materials, such as glass fibers or chopped wires, and/or reinforcement structures such as steel wires or bars may be added to the liquid wall material before it solidifies. After the wall material solidifies, the reinforcement materials are embedded therein. The reinforcement materials may include reinforcement bars, also known as rebar, used to construct an internal structure inside the wall. Concrete walls having an internal rebar structured embedded therein are often referred to as “reinforced concrete walls.”
Reinforced walls, such as reinforced concrete walls, resist deformation by transferring stress from the wall material to the embedded reinforcement materials. As a general rule, each of the individual wires or bars embedded in the wall material resist tensile stress in the direction of their longitudinal axis. Because tensile stress may occur in several directions, the reinforcement materials and/or structures constructed therefrom may include longitudinal members oriented along more than one direction.
For example, referring to FIG. 1A, a plurality of reinforcement bars 2 may be assembled (e.g., wired together) to form a two-dimensional grid-like structure 10. More than one two-dimensional grid-like structure 10 may be embedded in the wall material. For example, referring to FIG. 1B, the two-dimensional grid-like structures 10 may be coupled together to form a three-dimensional grid-like structure 20, sometimes referred to as a “cage.”
Referring to FIGS. 1A and 1B, in typical wall construction, the two-dimensional grid-like structure 10 or three-dimensional grid-like structure 20 rests upon a concrete footing 30. The grid-like structures 10 and 20 may be connected to rebar embedded in the footing 30 and exiting the top surface thereof, and/or attached to the footing 30 by other connectors known in the art.
During construction, the plurality of reinforcement bars 2 are typically disposed within a wall forming structure or system and the liquid wall material is poured into the form and cast around them. The wall forming structure or system may be constructed from sheet materials such as wood, metal, cast stone, styrofoam, cast Styrofoam, and the like. Generally speaking, the concrete or similar material may be poured between two confronting and spaced apart vertical sheets that are tied together in a transverse direction by a plurality of walers or ties. The sheet materials remain in place after the wall material has solidified and form layers of insulation along each face of the insulated wall.
Because wall materials are often hard and difficult to penetrate, it may be desirable to fasten attachment members or similar structures to one or both faces of the solidified wall material. If the face of the wall includes a layer of insulation, the insulation may be too soft to use as an attachment member. Further, attaching materials to the layer of insulation may damage it.
The attachment members may include strips of material such as wood, plastic, and the like that are softer than the wall material. If the wall includes an insulation layer installed along one or both faces, the attachment members may be harder than the insulating material and anchored to the wall material. The attachment members may include a portion that was introduced into the wall material while the wall material was in its liquid state. In this manner, the portion of the attachment member may be embedded in the wall material after it hardens and thereby anchored to the wall. Alternatively, the attachment members may be coupled to structures, such as ties, that are embedded in the hardened wall material before or after the liquid wall material is added to the wall forming structure or system and subsequently hardens. Alternatively, the attachment strips may be fastened to the face of the wall by glue, staples, nails, screws, and the like. Wall components such as siding, drywall, sheet insulation, and the like may be anchored to one or both faces of the wall by fastening the wall components to the attachment members.
In most wall-forming systems, the sheet materials are uprighted and maintained in place by support members. Several support member designs may be found in the prior art. For example, TFSYSTEM® insulated cement forms (Wisconsin Thermo-Form, Inc., 185 East Walnut St., Sturgeon, Wis. 54235) include a ladder-shaped elongated upright support member having an I-beam cross-sectional shape. The I-beam cross-sectional shape includes two substantially parallel flanges connected by a transverse member that is substantially perpendicular to both of the flanges. As mentioned above, the wall forming system may be constructed by arranging the insulating sheets into two confronting and spaced apart walls forming a cavity therebetween and tied together by a plurality of ties traversing the cavity. With respect to the TFSYSTEM® insulated cement forms, each of the insulating sheets is taller than it is wide and is approximately of equal height to the support members. The insulating sheets each include two opposing vertically extending end walls, each having a longitudinal slit extending inwardly from the end wall. The longitudinal slit extends along the entire length of the end wall and is open at both ends.
When the insulating sheets are arranged to form one of the walls of the wall forming system, one of the end walls of a first insulation sheet is placed adjacent to one of the end walls of a second insulation sheet and the longitudinal slit in the end wall of the first insulation sheet is placed adjacent to the longitudinal slit in the end wall of the second insulation sheet. The flanges of the I-beam are sized and shaped to be received into the adjacent longitudinal slits simultaneously. A portion of the end wall of the first insulation sheet is separated from a portion of the end wall of the second insulating sheet by a portion of the transverse member.
Each of the insulating sheets of the other of the wall of the wall forming system may be slid between neighboring support members by placing the insulation sheet atop the neighboring support members, aligning the slits of the insulation sheet with the flanges of the neighboring support members, and lowering the insulation sheet between the neighboring support members and thereby receiving the flanges inside the slits. Alternatively, the first and second walls of the wall forming system may be constructed simultaneously. The walls of the wall forming system are connected across the cavity by the transverse members of the support members.
The TFSYSTEM® insulated cement form system has several drawbacks. First, support members cannot be used to construct a wall forming system around a preexisting internal structure such as the two-dimensional grid-like structure 10 or the three-dimensional grid-like structure 20. Second, the end walls of the insulating sheets must be modified to include longitudinal slits. Third, special corner insulating sheets must be used to construct corners in the finished wall. Fourth, the flanges of the support members are embedded in the insulating sheets and cannot be used as attachment members.
Other prior art wall forming systems include Premere Insulating Concrete Forms (Premere Forms, Inc., 2309 West 50th Street, Sioux Falls, S. Dak. 57105-6568). The Premere Insulating Concrete Forms use rectangular insulating sheets that are oriented horizontally. An I-beam shaped elongated support member is positioned between neighboring insulating sheets. The support members of the first wall of the wall forming system are juxtaposed with the support members of the second wall of the wall forming system.
The I-beam shaped member includes an inside flange, an outside flange, and a transverse member extending therebetween. The transverse member has two planar sides, a top side, and a bottom side. One end wall of a first sheet is received into a first recess formed between the inside flange, the outside flange, and the first side of the transverse member. One end wall of a neighboring second sheet is received into a second recess formed between the inside flange, the outside flange, and the second side of the transverse member. In this manner, the outside flange is disposed along the outside face of the wall of the wall forming system and the inside flange is disposed inside the cavity.
The inside flange is disposed within the cavity and includes a rail having a generally arrow-shaped cross-section. A plurality of elongated ties having a fastener configured to receive, clamp, and hold the generally arrow-shaped rail are fastened between the rails of the first and second walls of the wall forming system. The fasteners may be snapped into place along the rail. The ties should be snapped onto a pair of rails (and thereby forming a ladder-shaped support member) before the support members are incorporated into the first and second walls of the wall forming system.
The Premere Insulating Concrete Forms have significant drawbacks. First, if the ties are attached to the support members before installation into the first and second walls, the Premere Insulating Concrete Forms cannot be used to construct a wall forming system around preexisting internal structures such as the two-dimensional grid-like structure 10 or the three-dimensional grid-like structure 20. Second, if the ties are to be snapped to the rails of the support members after installation into the wall forming system and the first and second walls of the wall forming system are not sufficiently parallel, snapping the ties to each of the rails across the cavity may be difficult, if not impossible. This becomes increasingly more difficult as the first and second walls increase in size and correspondingly weight. Third, the ties may slide along the rails. Consequently, the rails cannot be placed in an upright orientation or gravity will cause the ties to slide to the bottom of the wall-forming cavity between the first and second walls. Some types of elongated wall components, such as wood siding, vinyl siding, and the like, cannot be mounted to the horizontally extending outside flanges that form attachment members along the outside surface of the wall. Consequently, vertically extending strips must be attached to the outside flanges to provide an anchoring surface to which to mount such wall components. Attaching the vertically extending strips increases the expense and time required to construct the wall.
Another prior art system includes Quad-Lock Insulated Concrete Forms (Quad-Lock Building Systems Ltd., 7398-132nd Street, Surrey, BC V3W 4M7, Canada). This wall forming system includes a pair of identical and connected I-beam shaped support members each having a first flange, a second flange, and a transverse member extending between the first and second flanges. The support members are connected together by two spaced apart connecting members extending between the transverse members of the support members. Like the structure of the TFSYSTEM® insulated cement form system, the flanges of the support members are received into slits formed in an end wall of the insulating sheets. However, each of the connected I-beam support members extends only a short distance along the length of the insulating sheet. The insulating sheets also include projections formed along the same end walls as the slits. An elongated plate including apertures sized and spaced to receive the projections is attached to the end walls of the insulated sheets. Like the TFSYSTEM® insulated cement form system, this system has the drawback of requiring insulating sheets with slits formed in two opposing end walls and has the further drawback of requiring the formation of projections in those same end walls.
Therefore, a need exists for improved methods of constructing insulated walls. A need also exists for a wall forming system that does not require custom or modified insulating sheets. Further, a need exists for wall forming systems that may be constructed around reinforcement materials and/or structures. A need also exists for a wall forming system that allows the ties connecting the insulating sheets on opposite sides of the cavity to be readily connected to the insulating sheets.